The present invention relates to a capacitance detection type record stylus which detects signals stored in the form of minute pits along tracks on a recording medium as geometric variations, and a method for making such styluses.
Various attempts have hitherto been made to provide a capacitance detection type record stylus which is resistant to abrasion that occurs as a result of contact with the surface of a capacitance disk spinning at significantly high speeds. More specifically, the stylus comprises a diamond body provided with an electrode extending downwardly to a face that makes contact with the record surface. To ensure a high degree of resistance to wear the electrode needs to be bonded strongly to the underlying crystallographic structure of carbon atoms that constitute the diamond body so that the conductive atoms are not dislocated under the rigorous conditions.
The prior art attempts involve bombarding the diamond body with high velocity conductive particles such as hafnium or titanium, or using similar techniques, to permit conductive atoms to penetrate into the diamond to form the electrode. However, satisfactory results have not been obtained due to the fact that the surface of the diamond on which the electrode is to be formed tends to present an obstacle to the introduction of particles and lattice defects occur in the bombarded crystal structure.